Stop motion for spring needle knitting machines



March 13, 1951 voss 2,545,324

STOP MOTION FOR SPRING NEEDLE KNITTING MACHINES Filed Aug. 16, 1949 2 Sheets-Sheet 1 Q DffFC/DK jw/m/ a INVENTOR ATTO R N EY March 13, 1951 E. VOSSEN 2,545,324

STOP MOTION FOR SPRING NEEDLE KNITTING MACHINES Filed Aug. 16, 1949 .2 Sheets-Sheet 2 W ATTORNEY Patented Mar. 13, 1951 STOP MOTION FOR SPRING NEEDLE KNITTING MACHINES Edward Vossen, Lynbrook, N. Y., assignor to, Stop-Motion Devices Corp., Brooklyn, N. Y., a

corporation of New York Application August 16, 1949, Serial '1 Claims. (01. (so-#159) This invention relates to new and useful improvements in stop motions for spring needle knitting machines having a retractable presser foot for each yarn feed, of the type as embodied in the knitting machines of Tompkins Bros. and

Crane, and other machines using spring beard needles.

On spring needle knitting machines, the spools or cones of yarn are usually run off the floor, or off wooden platforms, the yarn feeding upwards through porcelain guides directly into the feeds of the machines. .Heretofore, stop motions have not been very successful on spring needle machines. For this reason there are large numbers of these machines operating without stop motions of any kind. There are several reasons why prior stop motions have been objectionable. To understand these objections it must first be noted that prior stop motions used on these machines included bottom knot and end detectors 'placed above the cones or spools, and top knot and end detectors placed high up over the machines. The yarns are threaded through the bottom detectors and then up to the top detectors high above the machines, and then down again into the feeds of the machines. Because the yarn runs from below to the top detectors and then down again into the feeds, there is undue tension on the yarns which affect the stitch, producing poor fabric because of the abnormal drag 3 on the yarn caused by the fact that the top detectors are so high up. The reason that the top detectors are placed so high up is to allow sufficient slack in the yarn between the time that the controllers of the knitting machines knock offand the actual stopping of the knitting machines. Many of these knitting machines do not employ brakes and therefore the momentum carries the machines around completely. Without the use of a stop motion, a broken or loose end causes a complete press-off. Often the use of brakes on these particular types of machines is not feasible because the swing is so great that a sudden stop could damage the machines.

Another undesirable feature of the overheadv type of detectors is that the yarns then form a picket fence around the machines in such a manner that the operator has to wade in between the threads in orderto adjust the machines.

, Another deficiency of the usual overhead detectors employed on these machines is that when the yarn is released from the overhead detectors it falls down on the machines and becomes twisted and entangled in the needles and feeds.

-An important object of this invention resides."

in the construction of a stop motion for spring needle knitting machines which does not require that the yarn be guided up over high .top detectors. In fact, it is proposed that the new stop motion, in accordance with this invention, merely requires that the yarn extend from the spools or cones directly to the feeds of the knitting machines and no higher. This new stop motion eliminates the overhead detectors entirely.- Because the yarn runs directl from thespools or conesto the feeds through suitable bottom and end detectors, the unwarranted drag of prior stop motions has been entirely eliminated, thus eliminating the prior. poor work performed by these machines equipped with the old overhead type of detectors. With the new stop motion there are no picket fences of yarn around the machines so that the machines are readily accessiblevto the operator. for adjustmentand repair. -Obviously, since the yarn does not extend above the knitting machines there is no possibility of-the yarns dropping down and becoming twisted and entangled in the needles and feeds of the machines.

A characteristic of spring needle knitting machines resides in the factrthat the needles are capable of throwing off the yarn stitches only aslong as the presser feet are in engagement with the needles. This invention particularly proposes to provide av stop motion device capable of disengaging the presser feet from the spring needles upon the operation of any detectorinorder to prevent a press-01f.

A further object of this invention resides in the provision of means for instantaneously, cutting the yarn to a particular feed which causes the stop motion to operate in order to prevent the yarn from being fed into the knitted material after a particular feed has ceased to operate because its presser foot was retracted by the stop motion. This prevents visible damage to the knitted material, The fact that one feed ceases to operate does not produce a readily detectable defect.

The new stop motion, in accordance with this invention, is also provided with a master controllerwhich instantly trips the starting handle of the knitting machine to cause the machine to come to a gradual stop-upon the operation of one or more of the detectors of the stop motion.

Another object of the invention is the constructionof a device as described which is simpleand durable and which may be manufactured. and

sold at a reasonable cost.

- open by the yarn 2|.

motion for a spring needle knitting machine con- The electric controlled means l3 for retracting said presser foot II includes a yoke 30 connected with said presser foot II by engaging the bottom end of the rod 22. This yoke 30 is in the form of a strand of Wire bent at the center. The bent center of said yoke 30 engages around said rod: 22, said, yoke-3E! being. disposed at right angles to the length of said rod 22. The yoke 30 is supported by having its ends mounted upon a Fig. 3 is a sectional view taken on the line 33 of Fig. 2.

Fig. 4. is a fragmentary enlarged sectional Viewv taken on the line 4-4 of Fig. 3.

Fig. 5 is a schematic wiring diagram of the de.- jvlc'e'.

The stop motion for a spring needle knitting machine which has. its cylinder of spring needles schematically illustrated and indicated in Fig. 1

by the dot and dash lines [0, has a retractable I presser foot I I for each yarn feed [2. Inaccordance with this invention the stop motion includes the knitting machine. The details of this controller M will not be given in this specification since it. forms no part of the invention, and con:-

trollers of this type. are. generally known. The @controller [4 includes a normally closed switch [5 when the controller is on and which opens when the controller snaps off. to stop. the knitting machine. I6 is provided for each yarn for protecting the yarn feeds of the knitting machine, and these detector switches I6. are. operated by the yarns of said feeds identically in the same way as the knot and end detector switches .of presentyday stop motions on knitting machines- An e ectric. circuit l9 connects said electric controller l4 with A knot and end. detector switch said electric controlled means 13, and with said detector switches I6 for operating one of said electric controlled means 13 and said controller I 4 whenever the detectorswitch H; of one of the ment screw 23 on a plunger 24 which operates in the cylinder 25 mounted on a supporting bracket 26. In the on position, the presser foot H engages the spring needles ID of the I knitting machine. In the off position the pressure foot I I is moved slightly to the left so as to disengage from the needles 7 I 0 of the knitting machine. In the latter condition the needles are .1' incapable of throwing off the yarn and this preventsa press-off. When thepresser foot ll enj. gages the needles, and a yarn is broken, the needles are capable of throwing off the yarn and a complete press-off occurs' unless the knitting machine is stopped in time.

The detector switches [6 are normally held As soon as a knot or other obstruction, or an end of the yarn reaches the detector switch IE it closes, in order to operate the stop motion.

This bar 3| is fixedly mounted at its center across and upon a rack 32. The rack 32 is horizontally slidably mounted in a stationary bracket 33. A, shaft. 34 is turnably mounted in the bracket 33 and extends at right angles to therack 32, and said shaft is provided with a pinion 35 engaging said rack 32 by which the rack 32 may be retracted. Said shaft 34 is resiliently urged to retract the rack 32 by a spring 36. The spring 36 is attached at one end by a screw 3'! upon a bushing 38 mounted on the shaft 34. The other end of the spring 36 connects with a clip 39 mounted upon the bracket 33. A handle 40 is mounted upon one end of the shaft 34 by which said shaft 34 may be turned and the said electric controlled means. I3 may be manually set in an on position.

The electric controlled means l3 also includes an electromagnetic latch for normally indirectly holding said yoke 30' forwards. This electromagnetic latch includes coils 42with cores fixedly mounted on a bracket 43 attached tdthe bracket '33". An armature 44 is pivotally mounted by a trunnion or pintle 45 upon the bracket 13. This armature 44 is attracted by the'cores of the coils 42 when the latter are energized. A leaf spring 46 mounted upon the armature 44 normally urges the armature 44 away from the cores of the coils 42. A stop finger 41 from the bracket 43 limits pivoting of the armature 44 away from the cores of the'coil's 42. A trip arm $8 is radially mounted on the shaft 34 and is engageable by and held by said armature 44 when the coils 42 are de-energized. The armature 4 t isprovided with an ofis'et end 49 against which an. inturned end iii of the trip arm 48: engages. This offset end 49 is provided with a cam surface 53 against which the inturned end El of the trip arm :8 may engage when the electric controlled means i3 is manually moved to its on position by moving the handle 48.

The yoke 33 is associated with. adjustable means for limiting its motion to its retracted position. This adjustable means merely comprises adjustments screws 52 threadedly mounted on the bar 3! and engageable against one face of the bracket'33. The electric controlled means 93 includes a selector switch 51 consisting of a contact arm- 54 and two contacts, namely, an on contact 55 and an off contact 53. This selector switch 5'! is mounted on an insulation strip 58 mounted on a support 59 attached to the bracket 33. The selector switch 31 is operated by a lever 53 engaging said trip arm 48 for holding said contact 54 upon said contact 55'. Said switch 51 is provided with a spri. g ti which moves the contact arm 54' upon contact 53 when the trip arm "48 is freed by said armature 44 and moves to its 01f position. A casing Bil is engaged upon each bracket 33 and covers the selector switch 51, the spring 36, the coils 42, the trip arm 48, and several other parts as may be readily seen by inspecting the drawing. 7

Each detector switch it is connected in series with the coils 42 of one of the electro-magnetic 7 latches of its electric controlled means 13 for retracting one of said presser feet I I. In the "on position of the selector switches 51 the coils 42 of each of said means I 3 is connected in parallel in said circuit 19. In the off position of each selector switch 51 the off contacts 56 are connected in parallel with each other and in series with said controller l4.

Each thread cutting means includes a stationary tube 65 mounted upon the side of the casing 60. Each tube 65 has a porcelain eyelet 66 on one side through which the yarn 2| passes, and an aperture 61 diametrically opposite the eyelet 66 through which the yarn 2| also passes. A shearing knife 68 is cooperative with the aperture 61 for cutting 'the yarn 2|. This shearing knife 68 has a hub portion 69 which is fixedly mounted upon one end of the shaft 34. i

The operation of the stop motion for a spring needle knitting machine, in accordance with this invention, may be understood from the following: 1

The electric control means l3 are illustrated in on positions. The trip arm 48 is illustrated engaging the offset end 49 of the armature 44 representing the on position of the device. With the parts in this position the yoke is in its forward position so that the presser foot H is in a corresponding forward position engaging the spring needles of the knitting machine. When the selector switches 5'! are in their on positions the contact arms 54 engage the on contacts 55. The knitting machine may now be operated to knit material. Current does'hot flow in circuit l9 because the detector switches it are open.

Let us assume that a knot or other obstruction or an end of the yarn 2i comes along on one par ticular detector switch I 6. Immediately this particular detector switch i6 is closed. 'The circuit 19 is'now closed through one of the electric contro led means l3 for retracting one of said presser feet H. The current flows through the coils 42 of this particular electric controlled means 53, causing the coils to magnetize its core, attracting the armature 44. The leaf spring 46 is merely flattened out when the armature 44 is attracted. The motion of the armature 44 drops the trip arm 48, freeing the shaft 34. Immediately the spring 36 turns the shaft 34 a small distance as permitted by the adjustment screws 52 striking the bracket 33. As the shaft 3-4 turns, the pinion 35 will move the rack 32, causing the yoke 39 to be retracted and correspondingly retracting the presser foot H of the particular yarn feed l2 affected. As soon as the presser foot I! is retracted knitting at this particular feed ceases. This prevents a press-off.

The handle 53 of the selector switch 51 is released by the trip arm 48 and then spring 6! causes the contact arm 54 to engage the off contact 55, when the shaft 34 is turned by the spring 36. Now the electric circuit l9 supplies current to the controller M which instantly throws the starting handle of the knitting machine to its off position. When the shaft 34 was turned by the spring 35, the shearing knife 68 moved across the aperture 61 and sheared the yarn 2 to the particular feed I 2 controlled by the particular presser foot i l of the electric controlled means 53 which was just operated. Therefore, this yarn 2i of the particular feed l2 will not be wound around within the material being knitted by the other yarn feeds of the knitting machine.

The operator may reset the stop motion by moving to its on position the handle 40 of the particular electric controlled'means I3-which was operated by the particular detector switch It, after said detector switch it is opened by threading the yarn 2| through said detector switch and the affected feed of the knitting machine. Then the controller I4 is reset to its on position. When the handle 4!! is moved to the on position the shaft 34 was rotated to stretch the spring 36. Simultaneously the pinion 35 moved the rack 32 which moved the yoke 30 to its forward position. The trip arm 48 is moved by the shaft 34 so that the offset end 5| engages the cam 50, moving the armature 44 momentarily upwards while the offset end 5i engages behind the end 49 of the armature 44. The parts are now in their original positions. While I have illustrated and described the preferred embodiment of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims.

Having thus described my invention, What I claim as new and desire to secure by United States Letters Patent is:

l. A stop motion for a spring needle knitting machine having a retractable presser foot for each yarn feed, comprising an electric controlled means for retracting each of said presser feet, an electric controller for stopping said knitting machine, a detector switch for each of said electric controlled means for protecting its yarn feed and operated by the yarn of said feed, an electric circuit connecting said electric controller, said electric controlled means, and said detector switches for operating one of said electric controlled means and said controller whenever the detector switch of said one electric controlled means operates, and thread cutting means for each of said yarn feeds for cutting theyarn to the particular feed protected by the detector switch which operated, each of said electric controlled means including a yoke connected with its said presser foot, means urging said yoke to retract said presser foot, and electro -magnetic means for normally holding said yoke forwards.

2. A stop motion for a spring needle knitting machine having a retractable presser foot for each yarn feed, comprising an electric controlled means for retracting each of said presser feet, an electric controller for stopping said knitting machine, a detector switch for each of said electric controlled means for protecting its yarn feed and operated by the yarn of said feed, an electric circuit connecting said electric controller, said electric controlled means, and said detector switches for operating one of said electric controlled means and said controller whenever the detector switch of said one electric controlled means operates, and thread cutting means for each of said yarn feeds for cutting the yarn to the particular feed protected by the detector switch which operated, each of said electric controlled means including a yoke connected with its said presser foot, resilient means urging said yoke to retract said presser foot, and an electro-magnetic latch for normally holding said yoke forwards.

3. A stop motion for a spring needle knitting machine having a retractable presser foot for each yarn feed, comprising an electric controlled means for retracting each of said presser feet, an electric controller for stopping said knitting machine, a detector switch for each of said electric controlled means for protecting its yarn feed and f operated by the-yarnofsai'd. feed, an electric: circuit connecting said; electric. controller, said. electrio-controlled. means, and said detector switches for operating: one of said electric controlled means and said controller whenever the detector switch of. said one electric controlled means operates, 1

and thread cutting means for each of said yarn feeds for cutting the yarn to the particular feed protected by the detector switchv which operated, each of said electric controlled means. including a yoke connected with its said presser foot, resilient means urging said. yoke to retract said presser foot, and an electro-magnetic latch for normally holding said'yoke forwards, said resilient means including a rack connected with. said yoke, apinion engaging said rack, a shaft for said pinion, and a spring urging said shaft in one direction.

4. A stop motion for a spring needle knitting machine having a retractable presserfoot for each yarn feed, comprising an electric controlled means for retracting each of said presser feet, an electric controller for stopping said knitting machine, a detector switch for each of said electric controlled: means for protecting its yarn feed and operated by the yarn of said feed, an electric circuit connecting said electric controller, said electric controlled means, and said detector switches for operating one of said electric controlled means and said controller whenever the detector switch of said one electric controlled means operates, and thread cutting means for each of said yarn feeds for cutting the yarn to the particular feed protected by the detector switch which operated, each of said electric controlled means including a yoke connected with. its said presser foot, resilient means urging said yoke to retract said presser foot, and an electro-magnetic latch for normally holding. said yoke forwards, said resilient means including a rack connected with said. yoke, a pinion engaging said rack, a shaft for saidpinion, and a spring urging said shaft in one direction, and a handle mounted on said shaft by which said electric controlledmeans may be manually set in an on position.

5. A stop motion for a spring needle knitting machine having. a retractable presser foot for each yarn feed, comprising an electric controlled means for retracting each of said presser feet, an electric controller for stopping said knitting machine, a detector switch for each of said electric controlled means for protecting its yarn feed and operated by the yarn of said feed, an electric circuit connecting said electric controller, said electric controlled means, and said detector switches for operating one of said electric controlled means and said controller whenever the detector switch of said one electric controlled means operates, and thread cutting means for each of said yarn feeds for cutting the yarn to the particular feed protected by the detector switch which operated, each of said electric controlled means including a yoke connected with its said presser foot, resilient means urging said yoke to retract said presser foot, and an electro-magnetic' latch for normally holding said yoke forwards, said resilient means including a rack connected with said yoke, a pinion engaging said rack, a shaft for said pinion, and a spring urging said shaft in 5' one direction, said electro-magnetic latch having. a coil, and. an. armature attracted by said coil when energized, and a trip arm, radially mounted on said, shaft and engageable by and held by said armature when said. coil. is de-energized.

6.- A stop motion for a spring needle knitting machine having a retractable presser foot for each yarn; feedi, comprising an electric controlled means for retracting each of said presser feet, an electric controller for stopping said knitting machine, a detector switch for each of said electric controlled. means for protecting its yarn feed and operated by the yarn of said feed, an electriccircuit connecting. said electric controller, said electric controlled means, and said detector switches for operatin one of said: electric controlled means and said controller whenever the detector switch. of said: one electric controlled means operates, and thread cutting means foreachof said yarn feeds for cutting the yarn to the particular feed protected by the detector switch which operated, each of said electriccontrolled means includinga yoke connected with its said presser foot, resilient means urging said yoke to' retract said presser foot, and. an electro-magnetic latchfor normally holding said yoke forwards, and adjustable means for limiting motion of said yoke to its retracted position.

7. A stopmotion for a spring. needle knitting machine having a, retractable presser foot for each yarnfeed, comprising an. electric controlled means for retracting each of said presser feet, an electric controller: for stopping said-knitting ma chine, a detector switch. for each of saidv electric controlled means for protecting its yarn feed. and operated by theyarn of said feed, an electric circuit connecting said electric controller, said electric controlled means, and said detector switches for operating one of said. electric controlled means and said controller whenever the detector switch. of said one electric controlled means operates, and thread cuttin means for each of said yarn. feeds for cutting the yarn to the particular. feed protected by the detector switch which operated, each of said. electric. controlled means including. a yoke connected. with its said. presser foot, resilient means urging said yoke to retract said presser foot, and an electromagnetic latch for normally holding said yoke forwards, saidv resilient means including a rack connected with said yoke, a pinion engaging said rack, a shaft-for said pinion, and a spring urging said shaft in one direction, said thread cutting means including a knife connected with said shaft, and-a member having an aperture through which said yarn passes, said knife shearing past said aperture when said electric controlled means operates to retract its presser foot.

EDWARD VOSSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 387,672 Yarwood Aug. 14, 1888 2,329,971 Ziock Sept. 21', 1943 

